Ok folks! This problem is definitly a bug in the DIR-615.
For some reason, DHCP just stops working.
I set all of my devices in the reserve list so I knew what IP was being doled out to what device. Set it up yesterday.
Today, I tried to get one of my laptops on the network and have the 615 dole out the reserve IP. The laptop would not get an IP.
As soon as I went into the laptops network settings and hardcoded the IP address that it was assigned by the 615 yesterday, all was good.
I removed the hardcoding and tried again to get a IP via DHCP. Would not work.
I then reset the 615 and low and behold, the laptop was able to get an IP via the 615 DHCP.
DLink, are you listening!? Fix this BUG!!!!!, please!